Mynydd Ceiswyn

Waun-oer is a mountain in Snowdonia, North Wales, situated approximately four miles to the south-west of Aran Fawddwy. It is one of the peaks in the Dyfi hills, a subgroup of the Cadair Idris group. It is a top of Maesglase and the summit consists of a trig point that crowns an uneven grassy plateau. It is connected to Cribin Fawr to the east and Mynydd Ceiswyn to the south. To the north lies Cadair Idris, while Tarren y Gesail lies to the west.

Cymerau quarry was a slate quarry served by the Ratgoed Tramway, a horse-worked section of the Corris Railway. It is located about half a mile north of Aberllefenni in Merioneth (now Gwynedd), North Wales, on the eastern side of the isolated Cwm Ceiswyn. It worked the Narrow Vein, the highest-quality slate vein in the Abercorris Group.

Mynydd Cambergi or Mynydd Cam-bergi is a mountain in southern Snowdonia, Wales. It is a summit on a long ridge between Mynydd y Waun to the north and Foel Grochan to the east. The mountain forms the north-east side of Cwm Hengae and sits about 0.5 miles (0.80 km) west of the village of Aberangell. Near the summit of the mountain lies the open pit of Cambergi quarry, which was worked from the 1870s to the 1890s.

Ratgoed quarry (also known as Alltgoed quarry) was the northernmost of the slate quarries served by the Corris Railway. It is one mile north of Aberllefenni in Gwynedd, Mid Wales, on the western side of Mynydd Llwydiarth. The quarry primarily worked the Narrow Vein, though it also produced some Broad Vein slates.

Yellow Aster Mine was a large gold mine in Southern California.

The Mach Loop (also known as the Machynlleth Loop) is a series of valleys in the United Kingdom in west-central Wales, notable for their use as low-level training areas for fast aircraft. The system of valleys lies 13 km (8 mi) east of Barmouth between the towns of Dolgellau to the north and Machynlleth to the south, from the latter of which it takes its name. The training area is part of the United Kingdom Low Flying System and lies within Low Flying Area 7 (LFA7), which covers all of Wales.

Cambergi quarry (also known as Wenallt quarry) was a slate quarry in Cwm Hengae, west of Aberllefenni in North Wales. It operated between 1873 and about 1895.

The Nant Ceiswyn (sometimes known as the Afon Ceiswyn) is a small river in Mid Wales. It flows from the northern flank of Mynydd Dolgoed down to Pont Cymerau, north-east of Aberllefenni. Here it joins the Nant Llwydiarth to form the Afon Dulas that flows south to the Afon Dyfi. There was an ancient bridge at Pont Cymerau.The valley of the river is often known as Cwm Ratgoed (or Ralltgoed), after the Ratgoed slate quarry about two miles north of Pont Cymerau. The quarry was connected to the Corris Railway at Aberllefenni by the horse-worked Ratgoed Tramway, which crossed the river as it passes Cymerau Quarry.To the east of the valley is Mynydd Ceiswyn, part of the chain of ridges running southwards from Maesglase.

The Nant Llwydiarth is a small river in Mid Wales. It flows from the southern flank of Mynydd Hendre-ddu down to Pont Cymerau, north-east of Aberllefenni. Here it joins the Nant Ceiswyn to form the Afon Dulas that flows south to the Afon Dyfi. There was an ancient bridge at Pont Cymerau.

Aberllefenni quarry is the collective name of three slate quarries, Foel Grochan, Hen Gloddfa (also known as Hen Chwarel) and Ceunant Ddu, located in Cwm Hengae, just to the west of Aberllefenni, Gwynedd, North Wales. It was the longest continually operated slate mine in the world until its closure in 2003. Foel Grochan is the quarry on the north side of the valley, facing Ceunant Ddu and Hen Gloddfa on the south; all three were worked as a single concern throughout their history. Rock was mainly extracted underground, though all three quarries had open pits as well.

The Narrow Vein Mudstone Formation (commonly known as the Narrow Vein) is an Ordovician lithostratigraphic group (a sequence of rock strata) in Mid Wales. The rock of the formation is silty, homogeneous or finely-laminated mudstone. It generally a medium blue colour. This formation has been commercially quarried as slate in several locations along its length. The formation is between 400 metres (1,300 ft) and 560 metres (1,840 ft) thick and runs from Dinas Mawddwy south-west to Cardigan Bay at Tywyn.

Cribin Fawr is a mountain in Snowdonia, North Wales, situated approximately four miles to the south-west of Aran Fawddwy. It is one of the peaks in the Dyfi hills, a subgroup of the Cadair Idris group. It is a top of Maesglase, connected to its parent peak by the Craig Portas ridge. The top of Cribin Fawr is a large open plateau of peat bog. To the west is Waun-oer, to the north Cadair Idris, to the south Maesglase and Glasgwm to the east.